Place your feet one foot-length (that’s your foot, not 12 inches) in front of the swiss ball.

Slowly squat down until your thighs are just below parallel to the floor.

Pause a second at the bottom.

Slowly get up squeezing your glutes.

Repeat the recommended number of times for your program.

Once you can do the ball squats for 15 reps continuously, it's time to move on to step 2.

Step 2: Squat with a support at your sides.

This time, lose your swiss ball and try to do the squats near a support you can hold on to.

Stand beside a table or a chair and hold on to it. Then squat.
Try to reduce your hand involvement over time. Watch the video below.

Once you've got used to this and can do 15 repetitions with no problems, try step 3.

Step 3: Squat with a low stool or chair behind.

Put a low stool behind you and squat as if you're sitting down on
it. However, try to just perch your bottom on it. Stretch out your arms
in front to help balance yourself.

Here's the video of me perching my bottom on a stool. :-D

Now after this, move on to step 4.

Step 4: Real squats exercise with arms stretched in front.

Now try to do the squats without any support. Stretch out your arms in front to help with balance. Watch the video below.

After this you should have mastered the proper squat technique. Now's the time to do full squats.

Step 5: Do full squats.

Just squat with your hands on your hips without any support at
all. Eventually try to go as low as possible without losing the tension.
If you can go very low, don't relax at the bottom position. Just stop
short of that level and come back up again.

Here's the video of the full squats.

Now that you can do a squats exercise properly, you can add weights
to make it harder. You can hold dumbbells, wear a heavy backpack or
carry a sandbag. The choice is yours.

Don't rush to use too much weight immediately though. Take your time and progress slowly and steadily. Have fun along the way!